                1. The field of the invention        
The present invention relates to a method of writing data to a large block of a flash memory cell, and more particularly relates to a method of writing data to a large block of a flash memory cell in which the data can be written continuously to a page even when the change of data is unable fully fill up the whole page.
2. Description of the Related Art
As the demand for NAND flash memory cell in the market is increasing, the productivity and the process technology are also upgraded accordingly, such as the development of new type of NAND flash memory cell, for example, a large block flash memory cell, a MLC flash memory cell and the like. And as technology is improved, the unit price of the flash memory cell is getting lower and lower. However, during the operation, the data storage or data retrieval of each page of the flash memory cell can be implemented only once at a time, and writing the data to the flash memory cell is limited by a sequence of operation, thus the processing speed of writing data to the flash memory cell is obviously reduced correspondingly.
The method of storing and retrieving data from the NAND flash memory cell can be generally described as follows.
Referring to FIG. 1, the controller picks one block from the preset back up blocks in the flash memory cell and use it as a buffer 11, and writes the unchanged data into the block 12 of the flash memory cell from the first page of the block 12 in an orderly manner, page by page to the buffer 11.
Referring to FIG. 2, if the changed data in the block 12 is enough to fill up a whole page, then the data will be written into the buffer 11 page by page according to the page number.
Referring to FIG. 3, if the changed data in the block 12 is insufficient to fill up a whole page, the processor uses the data 13 of the original block 12 to fill up the remaining free space and write to the buffer 11.
Furthermore, referring to FIG. 4, writing the unchanged data below the changed data in the block 12 in an orderly manner, page by page to the buffer 11 until writing of data in of the all pages is completed, then the original block 12 is erased to serve as a back up block, and the original block 12 replaced by the buffer 11.
However, the above conventional data writing method can only move data from the original block to fill up the remaining free space when the space in the page is not completely filled up when data change occurs, and when the data is not written continuously, writing speed will be significantly slow. In an electronic device, such as a computer, which uses this type of flash memory cell, the calculation and processing speed will be significantly reduced.